Altering the roof structure floor joists most roofs are constructed with internal support struts in the loft propping up the rafters and purlins horizontal roof beams in traditional cut and pitched roofs and making up the web of braces in modern trussed rafter roofs.
Loft conversion roof structure.
An almost flat roof is placed over the top.
These are suitable for most types of home including terraced house loft conversions.
Most loft conversions employ at least one pair of steel beams to support the new floor structure and the roof slopes at purlin level and sometimes also at ridge level e g.
Where you re adding a large dormer.
Changing the roof structure for a loft conversion.
In the roof space as the name suggests the ridge board is the length of timber which runs horizontally along the apex of the roof.
However the average dormer loft conversion with a double bedroom and en suite costs about 35 000 45 000.
This could be a hip to gable loft conversion or a mansard conversion for example.
This option is the most expensive as it requires the complex removal and rebuild of the existing roof.
Internal roof elements to consider during loft conversions consist of a number of sub structures such as ridge boards rafters purlins joists wall plates and steel beams.